Fallout 4 Walkthrough: Side Quest - Airship Down

- You’ll get this quest while speaking to Father in the wake of End of the Line. He gives you one final mission to carry out for the good of the Institute: taking down the Brotherhood of Steel. They’ve already tried to waste you once, so, what the hell, eh?

- Track down Madison Li in Advance Systems. She’ll outline the plan for the next mission in great detail, though it’s more simple than it sounds: get in, take out generators, deliver a Synth to a bigass robot. To help this along you’ll receive three Institute Beacons which will bring in some Synth support to help you in tight situations. You may want to hotkey these.

- Once you’re done with your prep, head to the teleportation room where you first entered the Institute. You’ll be zapped to Boston Airport the second you step on the pad, so make sure you’re absolutely ready.

Liberty Prime, the super weapon of the Brotherhood of Steel.Communists must perish!

Boston Airport

- Upon arrival you’ll appear in a small, abandoned warehouse on the edge of the Airport grounds. There are a few items to grab in here, but nothing special. Pop outside.

- Make your way south. A heavily-guarded entrance to the Airport is on your right, but if you crouch you can avoid being spotted. Use the fallen airplanes here to hide from the BoS Knights and Scribes on patrol, and when you come within sight of a hole in the wall where the waypoint is located, scan the walls for searchlights. If you can take these out quietly, do it. Getting into a fight here is not the end of the world - but you want to avoid the main entrance if you can, as there are so many dudes over here.

- The next area is a large storage room with plenty of transport crates, as well as a fair number of prowling BoS soldiers. Use the crates to keep away from patrolling guys - or just use them as cover to fire back. You should be able to make lots of noise in here without pulling in tons of soldiers from other areas. Keep your eyes open for Proctor Quinlan in here, as he’s carrying the unique Quinlan’s Armor.A Master locked door in here leads to a small area with a fair amount of ammo, as well as another Master locked door that will take you back outside.

- There’s a large bank of stairs in the rear of this area that leads to the upper floor, where you’re outside. Unless it’s dark and you’re really quiet, you’ll almost certainly get spotted going up, as there’s a landing pad with a parked Vertibird here - and when the Vertibird takes off, you’ll be staring at a cluster of BoS soldiers. Chuck a grenade right at these guys and you’ll take out the Generator they were guarding, even if you don’t take out any soldiers. That’s one down.

- Taking out one of the Generators will allow Synths to enter Boston Airport, and they’ll do so en masse. Sweep northwest after helping the Synths take out the Vertibird above and you’ll find another Generator at the rear of the structure on your left / right. West of this central structure is an elevator; at the top you’ll find the final Generator, guarded by a Protectron and two Turrets. Wipe out the lot with a few grenades. (Don’t freak out if you ‘see’ cloaked units during all this, they’re on your side.) Expect to run into Proctor Teagan in the process, who’s carrying Teagan’s Armor.

- Make your way north. There’s some stiff resistance ahead, but you’ll have lots of Synths to help you. The stairs up to Liberty Prime are on your right, and when you head up you’ll need to protect the Synth that’s busy hacking into Prime’s skull. This is quite easy, despite your exposed location, and all you really need to do is keep your health up long enough for the Synth to finish. Take down any Vertibirds that show up, and watch your back when the counter reaches 75%, as Elder Maxson himself will appear. He has a rather ridiculous laser weapon that will chew up your health better than anything anyone else has. Keep Liberty Prime between you and Maxson when you can. Once the ticker reaches 100% you’ll get zipped away from the Airport…

- … and, uh, well, you’ll see. Mission complete! Surviving long enough will earn you your experience, as well as one final quest: Nuclear Family. This one is short, and only requires you to speak with Father back at the Institute. Enjoy the ending! And the crapload of experience that comes with it!

- (As you might expect, this more or less spells the end of the Brotherhood of Steel in your game, and you won't run into random Vertibird raids anymore. You will, however, still find them camped out at the Cambridge Police Department, and they're understandably pissed at you.)